The present invention relates to a cooling or circulating fan assembly in which assembly and disassembly of the component parts are easily accomplished, and which assembly minimizes the criticality of manufacturing tolerances of the various components.
Heretofore, cooling fans, particularly those utilized in industrial environs have included a fan blade that rotates with a shaft and with a stationary shroud received about the fan blade, secured by separate brackets to the housing from which the shaft protrudes. Assembly of such a fan requires drilling special holes in the housing for receipt of the shroud mounting brackets. The brackets are assembled and secured to the housing, after which the fan blade is secured on the shaft. Finally the fan shroud is secured to the brackets. While such fan arrangements have successfully cooled the equipment with which they have been employed, certain problems have existed in the assembly and disassembly of same.
Particularly, the shrouds and fan blades have often been cast metal parts which are not normally manufactured under close tolerance. It is thus often necessary in the assembly of the prior art fans to make adjustments between the fan blades and the shroud to avoid interference therebetween during rotation of the fan blades. More specifically, in situations where initial testing of a prior art fan assembly indicated physical interference between the rotating blades and the shroud, it was necessary, prior to final inspection and testing, to adjust the shroud relative to the fan blades such that contact therebetween is avoided. Not only has such an arrangement been ineffective due to the need for adjustment, obviously also, should either the blade or the shroud be adequately out of tolerance, the part would be scrapped.
As mentioned above, during assembly of prior art cooling fans, three basic component parts have historically been involved, namely mounting brackets, fan blades, and a shroud. Each of the three components must be maintained in inventory for replacement of worn and/or damaged parts. Should replacement be necessary, the new part, whether fan blade or shroud may not match the other. Adjustment or matching of both new components may then be necessary, either of which would be both expensive and time consuming.
The present invention is directed to a unitized, quick-assembly fan arrangement which overcomes the problems of the prior art. There is no need for adjustment to compensate for manufacturing tolerances since there is no relative rotation between the blades and the shroud. The mounting brackets are also eliminated. Further, and importantly, a single, unitized fan system is provided at the point of manufacture that may be maintained in inventory of the end user. If replacement is then needed, it is only necessary to secure an assembly to the drive shaft. Such arrangement is not known to be taught or suggested by the prior art.